Volunteers in the Baltimore Longitudinal Study of Aging complete a detailed activity history questionnaire on most visits. A coding system has been developed which results in the computation of an average daily caloric expenditure value. In addition, these subjects perform maximal treadmill exercise tests. In the past few years, the maximal work equivalent is known (treadmill speed and slope) and maximal oxygen consumption is measured. Thus measures are available for general activity levels and for degree of physical conditioning. These estimates are being entered into a multiple regression program to evaluate their roles in determining blood pressure and serum lipid levels and glucose tolerance in BLSA subjects.